JP2009045148A - Device for testing bladder cancer and control method of the device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the number of ratings as false positive relative to the visual test; to reduce the time necessary for the image analysis; and to enhance the reproductivity in the bladder cancer test executed by quantifying the intravesical color fluorescent images. <P>SOLUTION: The device for testing bladder cancer is configured to photograph the fluorescence generated in a subject irradiated with an excitation light source 32 which emits excitation light for irradiating the subject by a color CCD image pickup part 20, to analyze the obtained image in an analysis part 42, and to find the R/B ratio. The average density of R, G and B components in coordinate points on a line set within a target examination area for the image is computed by the analysis part 42, and the R/B ratio as an index for the target examination area is obtained from the average density of the R component and the average density of the B component. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a bladder cancer inspection apparatus and a bladder cancer inspection apparatus control method, and more particularly to a bladder cancer inspection apparatus and a bladder cancer inspection apparatus control method in which an analysis process is performed on a fluorescence image.

  In the examination of bladder cancer, 5-aminolevulinic acid (5-ALA), which is a precursor of protoporphyrin IX (PPIX), is injected into the bladder, and red fluorescence emitted by the porphyrin is observed under excitation light, and bladder intraepithelial carcinoma Fluorescence cystoscopy to detect is performed. In this method, since a change in color tone is inspected visually, there is a problem that the sensitivity is high but the specificity is low and there are many false positives.

  Recently, it has been proposed to determine RGB components in an image by analyzing the image obtained by imaging the inside of the bladder with a color CCD under excitation light, and in particular to identify false positives by focusing on the ratio of RG components Has been.

  Non-Patent Document 1 discloses a bladder cancer inspection apparatus based on quantification of fluorescence endoscope images. This bladder cancer test apparatus performs a bladder cancer test by quantifying an intravesical color fluorescent image captured by a color CCD camera in a state where 5-aminolevulinic acid (5-ALA) is injected into the bladder. is there.

By injecting 5-ALA, porphyrin is accumulated in the cells, malignant bladder tissue is selectively stained, and contrast with surrounding normal tissue is considered to be clear. The acquired image is stored in the storage means of the computer, and image analysis is performed. Consider the density of the red component (R) and blue component (B) in the image. It is considered that the red component shows the fluorescence of protoporphyrin IX and the spontaneous fluorescence of the red tissue, and the blue component shows the diffuse backscattering excitation light. The R / B ratio in the selected window in the fluorescence image is determined and normalized with respect to the reference fluorescence. By setting the R / B threshold value to 1.1 and making a determination based on this threshold value, the false positive rating constant can be reduced.
D. Zaak et al. “Quantification of 5-aminolevulinic acid induced fluoresceence impulses the specificity of bladed cancer detection, 16th year, 16th year, 16th year.

  It is difficult to detect bladder intraepithelial carcinoma by visual inspection of the bladder. In bladder cancer testing by quantification of intravesical color fluorescent images as shown in Non-Patent Document 1, false positive rating constants can be reduced compared to visual ones, but images acquired for each specimen The analysis process of obtaining R / B in the selected window requires time, and the reproducibility of the obtained results was not good.

  The present invention has been made to solve the above-described problems, and a bladder cancer inspection apparatus according to the present invention includes an illumination unit having at least an excitation light source that emits excitation light for irradiating a subject, A bladder endoscope unit including a light transmission unit for irradiating the subject with light and a light transmission unit for transmitting an image of fluorescence emitted by the subject, and an image of the fluorescence attached to the bladder endoscope unit And an image analysis processing unit that performs image analysis processing on the image acquired by the imaging unit, and the image analysis processing unit is set in an inspection target region of the acquired image. R, G, and B component density average values at each coordinate point on the line are obtained, and an R / B ratio that is an index for the inspection target area is obtained from the R component density average value and the B component density average value. It is what

  In addition, the bladder cancer examination apparatus according to the present invention includes an illumination unit having at least an excitation light source that emits excitation light for irradiating a subject, a light transmission unit for irradiating the subject with light from the illumination unit, and a subject. Acquired by a bladder endoscope unit including a light transmission means for transmitting an image by fluorescence emitted from a specimen, an imaging unit attached to the bladder endoscope unit and imaging the image by fluorescence, and acquired by the imaging unit An image analysis processing unit that performs image analysis processing on the image, and the image analysis processing unit performs R, G, and R at each coordinate point on a plurality of different lines set in the inspection target region of the acquired image. An average value of the B component is obtained, an R / B ratio for each line is obtained from the average value of the R component and the average concentration of the B component for the plurality of lines, and an average value of the R / B ratio for each line. The final inspection object It may be those as determined as an index to become R / B ratio for frequency.

  You may make it discriminate | determine whether the site | part of the said test object area | region is a normal site | part or a tumor site | part by comparing R / B ratio calculated | required in the said image analysis process part with the threshold value prescribed | regulated previously.

  The illumination unit may include an excitation light source and an observation light source, and may be selectively used by a switching operation.

  According to the method for controlling a bladder cancer inspection apparatus according to the present invention, an image analysis processing unit analyzes an image obtained by capturing an image of fluorescence generated as a result of irradiating a subject with excitation light emitted from an excitation light source. A method for controlling a bladder cancer inspection apparatus, wherein the concentration average values of R, G, and B components at each coordinate point on a line set in the inspection target region of the acquired image are obtained; The R / B ratio serving as an index for the inspection target region is obtained from the average density value of the R component and the average density value of the B component.

  In addition, the method for controlling the bladder cancer inspection apparatus according to the present invention includes an image analysis processing unit that analyzes an image obtained by capturing an image of fluorescence generated as a result of irradiating a subject with excitation light emitted from an excitation light source. A method for controlling a bladder cancer inspection apparatus that performs processing, wherein the concentration average values of R, G, and B components at each of coordinate points on a plurality of different lines set in an inspection target region of the acquired image And calculating the R / B ratio for each line from the R component density average value and the B component density average value for the plurality of lines, and finally calculating the R / B ratio average value for each line. It is good also as what consists of calculating | requiring as R / B ratio used as the parameter | index about the said test object area | region.

  The obtained R / B ratio may be compared with a predetermined threshold value to determine whether the region of the examination target region is a normal region or a tumor region.

  In the present invention, the time required for image analysis processing is reduced by obtaining the R / B ratio from the density average values of the R, G, and B components at each coordinate point on the straight line set in the examination target region, and clinical In application, it is possible to determine the property of the inspection target area in real time, and to perform inspection with high accuracy and high reproducibility.

  In bladder cancer examination using the bladder cancer examination apparatus according to the present invention, an image obtained by irradiating a subject with excitation light and imaging the resulting fluorescence by a color CCD imaging unit attached to an endoscope is obtained. By performing the analysis process, false positives are reduced and specificity is improved.

  FIG. 1 shows a configuration of a bladder cancer inspection apparatus according to the present invention. This bladder cancer inspection apparatus includes a bladder endoscope 10, a color CCD imaging unit 20, an illumination light source unit 30, a control analysis unit 40, as a whole. A display unit 50 is provided.

  The endoscope 10 includes an insertion portion 11, an operation portion 12, and an eyepiece portion 13, and has an image guide fiber 14 and an illumination light guide fiber 15 inserted inside. The image guide fiber 14 transmits an image of the subject to the eyepiece unit 13 through a lens at the distal end of the insertion unit. The illumination light gad fiber 15 guides illumination light from the illumination light source unit 30 to the distal end, and a portion between the illumination light source unit 30 and the operation unit 12 is inserted into the sheath.

  A color CCD imaging unit 20 is attached to the eyepiece 13 of the bladder endoscope. An image of the subject transmitted by the image guide fiber 14 of the endoscope is formed on the surface of the CCD 23 by the lens 22 through the filter 21. The image signal generated by the CCD 23 is transferred to the control analysis unit 40. A filter 21 that transmits only a wavelength of 440 nm or more is used.

  The illumination light source unit 30 has an observation light source 31 and an excitation light source 32 and is switched by a switching mirror 33. The observation light source 31 is a white light source such as a xenon lamp, and the excitation light source 32 is a D-light light source having a wavelength of 380 to 440 nm.

  The control analysis unit 40 includes a control unit 41 that controls the operation of the CCD imaging unit 20 and the illumination light source unit 30 and acquires an image of the subject, and an analysis processing unit 42 that performs image analysis processing on the acquired image. Storage means for holding the acquired image and image data in the analysis process. The control unit 41 performs light source switching and light emission operation control of the illumination light source unit 30, performs control of capturing an image by the CCD image capturing unit 20 in synchronization with the emission of excitation light, and acquires an image. Are controlled to be transferred to the analysis processing unit 41. In the analysis processing unit 42, with respect to the fluorescence image acquired by imaging with the CCD imaging unit 20 with the excitation light source 32 irradiated to the subject, the R component density and the B component density are determined from the RGB component densities. The ratio (R / B ratio) is obtained. The display unit 50 displays the acquired image, analysis processing result, and the like.

  The excitation light source 32 in the illumination light source unit 30 uses a light source that emits excitation light having a wavelength of 380 to 440 nm. When excitation light is irradiated with 5-aminolevulinic acid (5-ALA), a precursor of protoporphyrin IX (PPIX), injected into the urinary bladder about 2 hours before the test, it emits longer wavelength fluorescence. . It can be said that 5-ALA incorporated into the synthetic pathway in the mitochondria of cells becomes PPIX, and is excited by 400 nm light to emit fluorescence.

  In an imaging unit having a color CCD, imaging is performed by transmitting light having a wavelength longer than 440 nm, and the density of RGB components of the acquired image is obtained. For example, the spectral characteristics of the excitation light and the fluorescence are as shown in FIG. E is excitation light (380 to 440 nm), and F is a spectrum of fluorescence on the longer wavelength side generated by excitation light. On the observing side, only the fluorescence component can be received by transmitting through a filter that cuts a wavelength component of 440 nm or less.

  Among the fluorescent components, the R component has a peak at a wavelength of around 730 nm, and the fluorescent material PPIX taken into the tissue such as cancer emits fluorescence in response to excitation light from a light source of 380 to 440 nm. In addition to cancer, inflamed tissue, atypical epithelium (abnormal tissue one step before cancer), etc. may appear red, and even when the excitation light is tangential to the bladder mucosa, it may appear red.

  The B component is backscattered absorption light having a wavelength of around 400 nm, and is considered to be the color of excitation light, that is, the color of excitation light itself during fluorescent cystoscopy. The G component is autofluorescence and is weak fluorescence emitted from the tissue itself regardless of whether PPIX is absorbed or not.

  As an index in the examination of bladder cancer, it is useful to consider the ratio between the R component that is fluorescence from PPIX and the B component that can be said to be the color of noise. The R / B ratio can be understood in a form similar to the signal / noise ratio (S / N ratio) used as an index representing the performance of recording and reproduction in audio and video.

  In the image of the subject acquired by the imaging unit, the concentrations of the R, G, and B components are distributed, and include a tumor site and a normal site. Among these, as shown in FIG. 3, a region D in the image to be inspected is selected, and a plurality of different straight lines L1 and L2 are set in this region. Using these straight lines as the density cross section, the average values of the R, G, and B component concentrations at each coordinate point on the straight line are obtained, and then, from the R component density average value and the B component density average value, The R / B ratio is obtained. An average value of R / B ratios for a plurality of straight lines is obtained as a final R / B ratio for the region D.

  The R / B ratio is obtained by image analysis for various parts of the subject, and whether the part of the same subject is a normal part or a tumor part is confirmed by a separate examination. FIG. 4 shows the results of the R / B ratio obtained by image analysis for each part of the normal part and the tumor part. The number of cases is 21, the number of specimens is 22 normal parts, and the tumor part is 47 specimens. The R / B ratio distribution obtained is divided into a normal part and a main part. The horizontal axis categorizes histopathological benign (normal part) and malignant (tumor part). In both, the long horizontal line in the center is the average value, and the short horizontal lines above and below the standard error The upper and lower ranges of the diamond shape defined by the lines passing through the end points of these horizontal lines, that is, the range up to twice the interval from the average value to the average error up and down is the average value of the R / B ratio. It represents the 95% confidence limit range. From this distribution chart, the normal part and the tumor part have different R / B ratios, and the R / B ratio value is low in the normal part and high in the tumor part. It can be seen that both can be separated.

  From this, the image analysis processing unit of the bladder examination apparatus obtains the R / B ratio by image analysis processing of the image acquired for the subject and determines the property of the examination target part based on the R / B ratio. In addition, the R / B ratio value can be compared with the threshold value 1.1 to determine whether the site is a normal site or a site with a tumor.

  In the actual examination of 59 specimens, the error rate of the R / B ratio between a plurality of straight lines (the value obtained by dividing the R / B ratio difference of the plurality of straight lines by the average R / B ratio) is about It is about 10% and relatively small. For this reason, the R / B ratio obtained for one straight line is also used to discriminate the subject, but by using the average value of the R / B ratios obtained for a plurality of different straight lines, a more accurate index can be used. Can be evaluated with high reproducibility.

  It is a general-purpose computer to set one or a plurality of straight lines in a region D in an image, obtain an average value of density of R, G, B components at each coordinate point on the straight line, and obtain an R / B ratio therefrom. Is provided with general image analysis software (for example, Lumina Vision: Mitani Corporation). As described above, in order to obtain R / B by image analysis, the setting in the region D is not limited to a straight line. R and B at each coordinate point along the curve are not limited to a straight line. Similarly, the R / B ratio is obtained from the average value of the concentrations of the G components.

  Further, in the present invention, an operation of obtaining the R / B ratio from the density average value of the R, G, and B components at each coordinate point on the straight line set in the inspection target region is performed. It takes less time and is useful in the sense that it can be used to determine the properties of a region to be examined in real time when considering clinical application.

  The present invention is a bladder cancer inspection apparatus that analyzes a fluorescence image of fluorescence from a subject and obtains an R / B ratio that serves as an index for a region to be inspected, and such a bladder cancer inspection apparatus. This is also a method of controlling so as to obtain an R / B ratio as an index for the inspection target region.

It is a figure which shows the structure of the bladder cancer test | inspection apparatus by this invention. It is a figure which shows the example of the spectrum of an excitation light source and the fluorescence from a subject. It is a figure which shows the straight line set to the test | inspection area | region of the acquired image. It is a figure which shows distribution of R / B ratio about the normal site | part of a subject, and the site | part with a tumor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Bladder endoscope 11 Insertion part 12 Operation part 13 Eyepiece part 14 Image guide fiber 15 Illumination light guide fiber 20 Color CCD imaging part 21 Filter 22 Lens 23 CCD
30 Illumination light source unit 31 Observation light source 32 Excitation light source 33 Switching mirror 40 Control analysis unit 41 Control unit 42 Analysis processing unit 50 Display unit

Claims (7)

An illumination unit having at least an excitation light source that emits excitation light for irradiating the subject, light transmission means for irradiating the subject with light from the illumination unit, and light transmission for transmitting an image of fluorescence emitted by the subject A bladder endoscope unit having a built-in means, an imaging unit attached to the bladder endoscope unit for capturing an image of the fluorescence, and an image analysis processing unit for performing an image analysis process on an image acquired by the imaging unit The image analysis processing unit obtains a density average value of R, G, and B components at each coordinate point on a line set in the inspection target area of the acquired image, and a density average of the R component An R / B ratio that serves as an index for the region to be inspected is calculated from the value and the concentration average value of the B component. An illumination unit having at least an excitation light source that emits excitation light for irradiating the subject, light transmission means for irradiating the subject with light from the illumination unit, and light transmission for transmitting an image of fluorescence emitted by the subject A bladder endoscope unit having a built-in means, an imaging unit attached to the bladder endoscope unit for capturing an image of the fluorescence, and an image analysis processing unit for performing an image analysis process on an image acquired by the imaging unit The image analysis processing unit obtains an average value of density of R, G, and B components at each coordinate point on a plurality of different lines set in the inspection target region of the acquired image, and The R / B ratio for each line is obtained from the average density value of the R component and the average density value of the B component, and the average value of the R / B ratio for each line is finally used as an index for the region to be inspected. R / B ratio Bladder Cancer inspection apparatus is characterized in that so as to obtain. The R / B ratio obtained in the image analysis processing unit is compared with a predetermined threshold value to determine whether the region to be examined is a normal region or a tumor region. The bladder cancer inspection apparatus according to claim 1 or 2. The bladder cancer examination apparatus according to claim 1, wherein the illumination unit includes an excitation light source and an observation light source, and can be selectively used by a switching operation. A method for controlling a bladder cancer inspection apparatus in which an image analysis processing unit analyzes an image acquired by capturing an image of fluorescence generated as a result of irradiating a subject with excitation light emitted from an excitation light source. And determining an average density value of R, G, and B components at each coordinate point on a line set in the inspection target area of the acquired image; and an average density value of the R component and an average density of the B component A method for controlling a bladder cancer inspection apparatus, comprising: obtaining an R / B ratio that serves as an index for the examination region from a value. A method for controlling a bladder cancer inspection apparatus in which an image analysis processing unit analyzes an image acquired by capturing an image of fluorescence generated as a result of irradiating a subject with excitation light emitted from an excitation light source. And determining an average density value of R, G, and B components at each coordinate point on a plurality of different lines set in the inspection target area of the acquired image, and calculating an R component of the plurality of lines. The R / B ratio for each line is obtained from the density average value and the B component density average value, and the average value of the R / B ratio for each line is finally used as an R / B ratio that serves as an index for the region to be inspected. A method for controlling a bladder cancer testing apparatus, comprising: 7. The method according to claim 5, wherein the determined R / B ratio is compared with a predetermined threshold value to determine whether the region to be inspected is a normal region or a tumor region. The control method of the bladder cancer test | inspection apparatus of any one of these.

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